The Northern Lights were in the past used to explain how the spirits of the dead traveled to the Sun to be purified, before they were sent back again. Just like impure ore can be purified by fire and turned into pure metals, the Sun could purify the spirits of the dead. The purer the ore is, the more pure metal will be left after this process, but all ore will be purified by this and leave only pure metal.
The European idea is that in life we can grow or whither, we can become stronger or weaker than we were, and we can remain pure or fail to do so. In the end though, the Sky God weighs us in his hands (the Sun and the Moon) on the sky and if we are found too heavy (dishonour is heavy to carry) we cease to be (i.e. no punishment, no torture, no Hell!). If we are found light enough we are purified and sent back to life free of all dishonour.
The more honour we gained in life, the closer to the divine we start the next time we are born. To reach the divine we need to be honourable to start with, and to continue to gain honour for generations, without falling into the many pits life leads us past.
Always do the honourable thing.